And chaeles e



2 Sheets-Shet I.

Patented May 9, 1882 ATT'EST:

N. PETERS. PholvLill'wgnphun Washington, D. C

,g' 2 Sheets-Sheet 2.

A J. GLSMIT H & 0. ELBUELL. SIGNALING; APPARATUS FOR TELEPHONE I IEs;

N Z57.6Z1 Patented: May 9,1882.

6 F1924- 21) ml ATTLESTA v u. PETERS. Hmo-Lilhognpbor, Washiuginn. 0.1;

two subscribers lines.

. UNITED STATES PATE T OFFICE.

JAMES e. sMrrn, or HACKENSAGK, NEW JERSEY, AND oHARLns n. BUELL,

OF NEW HA EN, CONNECTICUT, ASSIGNORS or ONE-THIRD TO GEORGE w. nor, on MILFORD, CONNECTICUT.

SIGNALING APPARATUS FOR TELEPHONE-LINES.

SPECIFICATION forming part of Letters Patent No. 257,621, dated May 9, 1882.

Application filed March 3. 1882. (No model.)

To all whom it may concern: I

Be it known that we, JAMES G. SMrrI-I, of Hackensack, New Jersey, and CHARLES E. BUELL, of New Haven, Connecticut, have invented certain new and useful Improvements in Signaling Apparatus-for Telephone-Lines, of which the following is a specification.

Our invention relates to apparatus for employment at the central office of a telephoneexchange system; and the object is to provide a simple and effective means whereby alternate positive and negative currents may be sent to any line of the exchange for operating suitably-constructed polarized electro-magnetio call-bells at subscribers stations.

To this end our invention consists in the combination, with the telephone exchange switch by which any two lines may be connected, of suitable means for connecting any line of the exchange-system to a wire leading to the secondary of an induction-coil, andin the primary wire of said induction-coil constantly operating devices wherebya current flowing through the primary coil may be-rapidly interrupted, reversed, or varied in such a manner as to produce in the secondary coil alternate positive and negativeelectric currents.

I11 conjunction with our invention we may use at the subscribers stations polarized electro-magnetic call-bells of the ordinary construction, or of any other construction that may be found useful for the purpose of responding to rapidly-reversed line-currents.

The accompanying drawings illustrate some of the many devices that may be employed in carrying out our invention.

Figure 1 illustrates the combination of. the telephone-exchange switch with devices for pro ducing the necessary changes of circuits,iand also shows one kind of apparatus for producing the changes in the primary circuit of the induction-coil necessary to the production of reversed currents in its secondary. Figs. 2, 3, 4, 5,6, and 7 show modifications.

Referring to Fig. 1, N represents a telephoneexchange switch-board of any desired construction, that is adapted to connect the wires of any W represents the polarized call-bell of a subsuitable construction that is adapted to sever the connection of the line with the switchboard and normal ground and connect theline to a wire, 10, common to the lines and leading to the induction-coil apparatus by which the reversed currentsare produced, and, if desired,

through a switch by which the wire 10 may be placed in connection with a telephone transmitter and receiver. S represents such a switch adapted, as is indicated, to connect line 10 to telephone communicating apparatus M, and to break the connection leading to the secondary of the induction-coil. I

A represents an induction-coil of any desired construction, whose primary coil is included in a local circuit with a battery, H, the circuitot' which is rapidly closed and broken by an electromagnetic interrupter consisting ot'electro-magnet B, vibrating armature O, and contact-stop h, through which the circuit of a local battery, F. is closed to the coils of the electromagnet B. l i

D represents aspring-contact insulated from the armature-lever C, and adapted to come into contact with a stop,b, when the armature is attracted by the elcctro-magnet B, and to thus complete the circuit of the induction-coil primary and local battery H, through d 1), contact-spring D, and wire 0, connected to contact-spring. When the armature C is drawn against adjustable stop h by its retractor, contact at D, and therefore the circuit of local battery H, is broken, and at the same time the circuit of battery F through B is completed by standard f, contact h, armature-lever and wire 6. Under this condition of the parts the armature O is immediately attracted by electro-magnet B, thus breaking the circuit of F at the back contact of O, and causing the magnet B to be discharged,whereupon the retractor of the armature-lever acts and draws the armature back again into contact with the stop 11. Armature G is thus caused to vibrate. At every forward movement of the armature the spring D makes contact with I), thus completing the circuit of the battery for the primary of the induction-coil, while at every backward movement contact between D and b is broken, thus breaking the circuit. Reverse electric impulses are thus rapidly and constantly produced in the secondary of the induction-coil, and when wire is connected to any telephoneline the reversed currents will flow toline and cause rapid vibrations in the armature-levers of the polarized bells at subscribers stations.

Instead of employing two local batteries, F and H, we may by another arrangement of the circuits produce the same effects with one. Such an arrangementis shown in Fig. 2. Here standards f f and their contact-stops are connected to the same pole of local battery F, the other pole of which is connected through wire a to the electro-magnet B, and through wire 4 to the primary of induction-coil. Armaturelever O and itsinsulated spring-contact D are,

as before, connected respectively to electromagnet B and to one end of'the primary wire of the induction-coil.

The operation is substantially the same as before described in connection with Fig. 1. When the armature-lever is drawn forward by the electro-magnet B'the current from battery F through the induction-coil flows through 7r, wire 9,1), 1), c, d, while the circuit through electro-magnet B is interrupted, at h. The armature being immediately retracted, the circuit of the primary coil is broken, and the circuit of electro-magnet B is completed at h, and the operation is repeated.

Fig. 3 shows another arrangement, in which the tlow of current through the primary of induction-coil is partially interrupted by com plet ing a short circuit around it. When the armature of electro-magnet B is against its back contact-stop, h, the battery F flows in shortcircuit through'electro-magnet B, armature 0, contact-stop h, and standard f. When the armature is drawn forward the short circuit is broken and the battery F flows to the primary through f c d. The interruption of the short circuit demagnetizes B, and the Ietractor of 0 immediately acts so as to draw the armature against contact-stop h and complete the short circuit again. The operation is thereupon immediately repeated, and rapid interruption of the short circuit ensues, thus causing the flow of current through the primary to be repeatedly interrupted, with the same results in the secondary coil as before. It is of course-necessary that the coils of magnet B should be of considerably less resistance than the primary coil, or that an artificial resistance should be inserted in c or d.

Fig. 4 shows devices whereby the direction of current in the primary coil may be rapidly reversed without interruptions to its continuity, thus producing at each reversal corresponding reversed currents in the secondary of the induction-coil, wire 10, and any subscribers line which is for the time being con= adapted to be carried byits resiliencyintocontact with an insulated metallic hook connected by wire bwith the same end of the primary coil as the hook first mentioned. The hooks and the springs are here shown asall insulated from one another, although it is evident that the two hooks might be electrically connected through the supporting-post and a single wire run from the post in place of the wires m and d. 0 represents a vibrating lever kept in constant vibration by any suitable means-as, for instance, by the action of 'electro-magnet 13 upon one side and a retractor upon the other, the circuit of a local battery through electromagnet B bein gautomaticall y made and broken through a back contact-stop, h, in a manner thatis evident. To one end oftheleverO is connected aconducting-pimp,adapted or arranged as the lever vibrates to alternately press the springs r 8 out of contact with the hooks, so that first one and then the other completes a contact with a hook. When one spring is in contact with a hook the other is pressed out of contact with its hook by the pin p, with which latter it is-for the time being in electrical connection, and thus with the lever G,

and through wire 0, with the opposite end of the primary wire from that with which wires m (I are connected. When spring 1' is in contact with its hook the negative pole, say, of the battery H is in connection with one end of the primary coil through wire at, and its positive pole is connected to the other end' through 8, p, and c. When spring .9 is in contact with its hook the positive pole of the battery is connected through wire d with that end of the primary coil to which the negative pole was first connected, and the negative pole is connected to the other end through spring 1', (which is now pressed back from its hook,) contact-pin p, and wire 0. The direction of the current from battery H is thus by the vibrations of lever O rapidly reversed, and

corresponding reversed currents are produced in the secondary coil. Suitable adjustingscrews are employed in the well-known manner for securing the proper relation of the parts. Other constructions of pole-changer may obviously be substituted for that here shown.

Fig. 5 shows a well-known construction, in

The other pole of the battery is connected by wire 0 with a similar spring, 8,

IIO

end of the induction-coil core.

which the core of the induction-coil takes the place of the electro-magnet B for vibrating the lever by which the desired changes in the cal current flowing through the primary coil are produced. G represents an armature-lever, the armature of which is presented to the The circuit of the primary coil and its battery F is through wire 6, primary coil, wire a,lever G, and, when the armature-lever is against its back contactstop, through stop it and wire d, to the battery. When the lever is in this position the core of the induction-coil attracts it and draws it forward, so as to break the circuit at h, whereupon the core loses its magnetism and the retractorof the armature immediately pulls it back again into contact with its stop, and the operation is repeated. As is evident, the makes and breaks of contact at It also produce the necessary interruptions of current in the primary coil. If the lever G be made to operate a pole-changer for reversing the primarycoil current, it is obvious that its armature should be polarized.

Fig. 6 shows a modification in which two reversely-wound primary coils are employed,

' and the current is caused to flow through first one and then the other. .C is the vibrating lever, kept in vibration by electro-magnet l3 and retractor in the manner before explained or in any other suitable manner. The end of thelever plays between two contact-stops, 7 and 8, forming the terminals of therevcrsely-wound primary coils, and is itself connected to one pole of a battery, the other pole of which is wheels connected to an escapement-wheel whose escapement-lever forms the vibrating controller. Fig. 7 indicates such a modification. B is an escapement-wheel kept in constant rotation by any suitable means, and O is an escapement-lever kept in constant vibration thereby. The lever 0 controls the circuits of the primary in any of the ways before explained or in any other suitable manner..

Many other mechanical devices may obvi-' ously be employed for vibrating thelever. The

rate'ot vibrating of the lever may be adjusted in any of the well-known ways. An adjustable weight, for instance, might be placed upon the lever. In the case of the electromagnetic devices for vibrating the lever the adjustment of the contact-screw through which the circuit of the operating electromagnet is completed will serve to accomplish the purpose.

What we claim as our invention is- 1. The combination, substantially as described, with the central-office apparatus of a telephone-exchange system for placing any two subscribers lines in connection with one another, of circuit-shifting apparatus for connecting any line to the secondary of an induction-coil, and in the primary circuit of the induction-coil a constantly-operatingcircuit-controller, whereby the currentfor the primary coil is suitably varied, reversed, or controlled in such a way as to produce reversed currents in the secondary coil and the connected subscrib- JAMES Gr. SMITH. CHAS. E. BUELL.

Witnesses to signature-of James G. Smith H. G. TowNsEND, Tnos. TOOMEY. Witnesses to signature of Chas. E. Buell:

W. H. HJKNIGHT,

F. H. KNIGHT. 

